1. Field of the Invention
The present invention relates to a rectangular crosshead design for a universal testing machine wherein the specimen pocket is machined at an angle to the front surface of the crosshead rather than perpendicular to the front surface.
2. Description of the Prior Art
In the prior art, the universal testing machine for determining tensile strength and similar characteristics of a sample is well developed. The testing samples in universal testing machines are typically held by jaws which are mounted in wedge-shaped pockets formed in crossheads. These wedge-shaped pockets of the crosshead and the jaws contained therein are configured and arranged to exert a holding force on the specimen. These pockets are typically machined with sides that are perpendicular to the exterior front and rear walls of the crosshead. While this prior art crosshead design is intuitively simple and well-adapted to its present uses and purposes, this results in a very heavy and expensive crosshead. Additionally, crossheads of the prior art may include offset cast portions for the apertures for receiving the columns of the universal testing machine. This, in particular, requires a large special shape casting to obtain the correct shape to work with a universal test machine. Purchasing a casting requires high upfront fees in the form of pattern charges and storage of the pattern. Additionally, castings of this size are more expensive than a purchased steel plate stock in the typical volumes employed.